As is known in the aeronautical industry, the rear of a fuselage 120 in an aircraft 110 is generally known as tail cone 121, which is shown in FIG. 1. The tail cone typically houses at least one Auxiliary Power Unit (APU) 122. The APU 122 is typically a gas turbine as is used to power the aircraft 110 with electric, pneumatic and/or hydraulic power, especially with the aircraft's main engines are not operating.
The APU 122 typically serves one or more of the following main functions:
(i) provide power to aircraft systems while the main aircraft engines 131, 132, are not running;
(ii) provide power to start the main engines 131,132, without need for a power source external to the aircraft;
(iii) provide power to the aircraft 110 while the aircraft 110 is waiting at an airport gate or is otherwise stationary and especially when the main engines are not running;
(iv) generate electrical power for aircraft systems; and
(v) provide hot air for the pneumatic systems, such as hot air for an air conditioning system and/or an anti-ice system in the aircraft.
A current trend of most aircraft manufacturers is to locate the APU 122 in the tail cone 121, to protect the cabin of the aircraft fuselage 130 in the event of a failure of the APU. The APU compartment is separated from the cabin a via a bulkhead firewall 123.
Inside the tail cone 121, the conventional construction used to maintain and stabilize the APU 122 is a support system 124. The support system 124 of APU 122 comprises a frame of rods or bars secured directly to a semi-single-hull structure of the tail cone 121. The support system 124 is shown in detail in FIG. 2.
To have access to the tail cone 121 and particularly to the APU and its ancillary systems 127a, 127b, it is common to have a door 125 on the underside of the tail cone 121.
The amount of unused space inside the APU compartment 126 is small. The space is becoming smaller because APUs 1222 and their ancillary systems 127a, 127b are becoming larger to meet increased demands for electrical power in modern aircraft 110 and to reduce the noise from the APU to meet increasingly stringent noise abatement regulations.
To install an APU 122 in the compartment 126, it is conventional to use a fish pole wire lift system 140, as shown in FIG. 3. The fish pole wire lift system lifts an APU from the ground and up into the APU compartment using wires suspended from hooks within the APU compartment. The tolerances are tight between the APU and the walls and other structures in the APU compartment, and are particularly tight with respect to the installation of the APU to the support system 124.
Due in part to the tight tolerances, APUs installed using fish pole wire lift systems 140 may become misaligned with respect to the support system 124 during installation, may become damaged during installation or damage the compartment or the ancillary components of the APU. Further, the installation process tends to be long when using a fish pole wire lift system. The installation process with a fish pole wire lift system 140 usually needs at least two operators each using respectively one of the control systems 141, 142 to install the APU 122 in the APU compartment 126. Also, fish pole wire lift systems 140 pose a danger in that the APU 122 may fall to the ground and injury an operator(s) if the wires break or come loose or the APU disengages from the wires.